1. Field of the Invention
The invention relates in general to a GAMMA adjustment method for a multi-channel driver of a monitor and a device of the same, and more particularly to a GAMMA adjustment method and a device thereof, which can effectively reduce an actual layout area of a driver.
2. Description of the Related Art
One of conventional multi-channel driver circuits for a digital monitor is a GAMMA adjustment method or a circuit device. Since different monitors have different channel quantities, a size of a layout area of the driver circuit is varied.
Referring to FIG. 5, a conventional data channel driver 60 is shown. The conventional data channel driver 60 includes a plurality of m-bit digital comparators 61, an m-bit counter 62, and a look-up table 63. Each of the m-bit digital comparators 61 includes two m-bit input terminals and a PWM output terminal. The two m-bit input terminals connect to an m-bit register D [m] separately. The m-bit counter 62 connects to an input terminal of one register D [m] of the digital comparators 61. The look-up table 63 includes a built-in mapping data for n-bits converting to m-bits, so as to provide for an n-bit input signal to look up a value from the look-up table to convert into an m-bit voltage signal. An output terminal of the look-up table 63 connects to the other register D [m] of each m-bit digital comparator 61. When an n-bit input signal of the driver 60 is input, the n-bit input signal is converted into a correspondent m-bit signal by the look-up table 63, and then the correspondent m-bit signal is output to the input terminal of each m-bit digital comparator 61 through the register D [m].
The above driver 60 utilizing a main function of the digital comparators 61 is used to compare an output signal of the counter 62 and an input signal of the driver 60, so as to output a driver signal to a correspondent data channel 51 of a monitor 50. Since an m-bit quantity of a counting signal is greater than an n-bit quantity of an input signal, i.e. m>n, the digital comparators 61 are required to choose an m-bit quantity as a the digital comparator, so as to be able to execute signal comparing. In this way, the n-bits input signal has to be converted into the m-bits signal by the look up table 63, so as to be able to input to the digital comparators 61 to be compared with the m-bits signal to output the driver signal successfully.
The quantity of the digital comparators 61 of the driver 60 corresponds to the quantity of the data channels of the monitor. Further, the two input terminals of each digital comparator 61 have to connect to two registers D [m] separately for keeping the input signal. Therefore, if the driver 60 is used for a monitor with multiple data-channels, a quantity of the digital comparator 61 and a quality of the register D [m] both significantly increase in multiple. Moreover, the conventional monitor has a high demand for a high resolution and pixel quantity; thereby the quantity of the drivers for the monitor is certainly increasing. Thus, the layout of the control circuit obviously becomes more complex and the cost is excessive. In order to prevent the driver circuits becoming the barrier to future development, a small-scale circuit layout and a low cost driver circuit design are necessary and even crucial for future monitor development.